Microtus longicaudus Merriam 1888

Wilson, Don E. & Reeder, DeeAnn, 2005, Order Rodentia - Family Cricetidae, Mammal Species of the World: a Taxonomic and Geographic Reference (3 rd Edition), Volume 2, Baltimore: The Johns Hopkins University Press, pp. 955-1189 : 1004

Microtus longicaudus Merriam 1888

Microtus longicaudus Merriam 1888 , Am. Nat., 22: 934.

Type Locality: USA, South Dakota, Custer Co., Black Hills, Custer, 5500 ft (1676 m).

Vernacular Names: Long-tailed Vole.

Synonyms: Microtus abditus A. B. Howell 1923 ; Microtus angusticeps Bailey 1898 ; Microtus angustus Hall 1931 ; Microtus baileyi Goldman 1938 ; Microtus bernardinus Merriam 1908 ; Microtus cautus J. A. Allen 1899 ; Microtus coronarius Swarth 1911 ; Microtus halli Hayman and Holt 1941 ; Microtus incanus Lee and Durrant 1960 ; Microtus latus Hall 1931 ; Microtus leucophaeus (J. A. Allen 1894) ; Microtus littoralis Swarth 1933 ; Microtus macrurus Merriam 1898 ; Microtus mordax (Merriam 1891) ; Microtus sierrae Kellogg 1922 ; Microtus vellerosus J. A. Allen 1899 .

Distribution: Rocky Mountains and adjacent foothills, from E Alaska and N Yukon, south through British Columbia and SW Alberta, Canada, to E California and W Colorado; including Pacific coastal taiga to N California; disjunct southern pockets in S California, Arizona, and New Mexico, USA.

Conservation: IUCN – Data Deficient as M. l. bernardinus , M. l. coronarius , and M. l. leucophaeus , otherwise Lower Risk (lc).

Discussion: Sometimes viewed as a Nearctic member of Chionomys ( Anderson, 1959) , or allocated to subgenus Microtus ( Chaline, 1974; Hall, 1981), or to subgenus Aulacomys ( Zagorodnyuk, 1990) . Although strongly differentiated relative to other North American Microtus (e.g., Hooper and Hart, 1962; Modi, 1987; Moore and Janecek, 1990), the phyletic affinity of M. longicaudus lies with this complex and not Old World Chionomys ( Chaline and Graf, 1988; Conroy and Cook, 2000 a; Gromov and Polyakov, 1977; Zagorodnyuk, 1990).

Extensive karyotypic (Judd and Cross, 1980) and molecular ( Conroy and Cook, 2000 b) variation reported, albeit not necessarily concordant, which invites continued taxonomic investigation. Well-defined geographic groupings of cytochrome b haplotypes interpreted in light of Pleistocene climatic changes, possible refugia, and likely isolation during northward reexpansion along different colonizing routes ( Conroy and Cook, 2000 b). Finley and Bogan (1995) discussed the inconsistent usage and problematic identification of subspecies ( alticola , mordax , and longicaudus ) in NW Colorado, an area which tellingly circumscribes some of the most distinctive populations (Southern Rockies Clade) identified by Conroy and Cook (2000 b) and whose genetic divergence approaches that of other Microtus species. Includes coronarius , which Jones et al. (1986) viewed as an insular derivative and subspecies of M. longicaudus ; MacDonald and Cook (1996) continued to list coronarius as species and advised broader comparisons with M. longicaudus populations to vindicate its status. See Smolen and Keller (1987, Mammalian Species, 271) .